This invention relates to sound effect generation, and, more particularly, to a sound effects generator for producing simulated automobile engine sounds.
Sound effects are often used in a variety of applications to simulate sounds or noises which typify the general or particular environment in which they are used. Thus, such generators find utility in various types of games, such as television games involving, for example, simulated motor racing or airplane flight or in the production of musical sounds, such as is shown and described in U.S. Pat. No. 4,783,812 of Kaneoka. Another frequently occurring use for a sound effect generator is in the production of realistic sounds for flight simulators which are used in pilot training, where it has been found that the addition of sound to the other sensory stimuli greatly enhances the realism of simulated flight. In U.S. Pat. No. 4,933,980 of Thompson there is shown such a sound effects generator in which simulated aircraft engine and simulated cockpit sounds are merged to produce a realistic ambience for the operator of the trainer, thereby providing, as closely as possible, realistic operating conditions.
Numerous arrangements exist in the prior art for altering already existing audio signals to produce a variety of sound effects. In U.S. Pat. No. 4,388,490 of Spector, there is shown an apparatus utilizing one or more signal processing modules, insertable in the apparatus, for achieving the desired sound effects. Other examples of altering audio signals to achieve desired effects are shown in U.S. Pat. Nos. 3,800,088 of Bode, 4,535,474 of Borish, et al. and 4,700,390 of Machida. The Borish et al. patent utilizes circuitry for selectively collecting, attenuating, and combining portions of signals stored in a memory to produce an audio signal with a fullness of sound referred to as ambience.
In a majority of the prior art systems, the sound effects are generated in response to various types of electronic control circuits, or, in the case of musical sounds, in response, for example, to the input of musical notes or tones to the generator. In the area of, for example, aircraft engine sounds, the sound effects are in response to electronic signals or triggering devices from within the system, and not from any signal input from an outside source or sources. Thus, it does not appear that there is any arrangement in the prior art for utilizing a signal input from an operating engine, for example, and altering and enhancing it to produce an engine sound that is characteristic of any of a variety of engine types, such as a V-8, in-line 8, V-12, or the like, or characteristic of a particular car, such as a Mercedes-Benz W-125 Grand Prix racer, or a Ferrari Testarossa. Such a system would furnish amusement to a vehicle operator, and, in certain instances, have the ancillary function of detecting engine problems.
In all of the foregoing prior art arrangements, the apparatus and associated circuitry, as well as the necessary signal processing to achieve the desired result, are extremely complex and, as is usually the case with electronic circuitry of complex design, costly. With the present state of the art of microchip capability, a system utilizing interchangeable microchips and a processing unit would greatly decrease the complexity and cost of the apparatus while achieving the desired sound effects.